%0 Journal Article
%T Limitations of red noise in analysing Dansgaard-Oeschger events
%A H. Braun
%A P. Ditlevsen
%A J. Kurths
%A M. Mudelsee
%J Climate of the Past Discussions
%D 2009
%I Copernicus Publications
%X During the last glacial period, climate records from the North Atlantic region exhibit a pronounced spectral component corresponding to a period of about 1470 years, which has attracted much attention. This spectral peak is closely related to the recurrence pattern of Dansgaard-Oeschger (DO) events. A red noise random process was used to evaluate the statistical significance of this peak, with a reported significance of more than 99%. Here we use a simple two-state model of DO events, which itself was derived from a much more sophisticated ocean-atmosphere model of intermediate complexity, to numerically evaluate the spectral properties of random (i.e., solely noise-driven) events. This way we find that the power spectral density of random DO events differs fundamentally from a simple red noise random process. These results question the applicability of linear spectral analysis for estimating the statistical significance of highly non-linear processes such as DO events.
%U http://www.clim-past-discuss.net/5/1803/2009/cpd-5-1803-2009.pdf